URL Encoding - reserved and unsafe characters

RFC 1738: Uniform Resource Locators (URL) specification is described in the following page. Also simple convertor is included.

http://www.blooberry.com/indexdot/html/topics/urlencoding.htm

Server.URLEncode(url)

applies these rules to the url. During getting an url parameter from the query string the value will be automatically decoded.

How to excute string with javascript

Simply use eval().

eval('peformAction()') will execute

Good working free CAPTCHA control for asp.net

CAPTCHA stands for "Completely Automated Public Turing test to tell Computers and Humans Apart" and means software peace which makes user input challenges which are easy for solving by humans and difficult for machines. The purpose is to avoid spam or hackers attacks which can harm your data or make unpredictable responses.

This post will show you one very good CAPTCHA control, which is tested by me and works fine, even with ajax. It is easy for use and will save you time to develop such control.

Thanks for Mondor software.
http://www.mondor.org/captcha.aspx

w3: A tool to troubleshoot client side issues.

HTTP Debugging Proxy:
http://www.fiddlertool.com/dl/FiddlerSetup.exe
It is good tool for analyzing http request by client side. You can view some errors that the server response don't show you.